A polycarbonate resin is widely used as one of engineering plastics in a plastic industry. A polycarbonate resin can have a glass transition temperature (Tg) reaching about 150° C. due to a bulky molecular structure such as bisphenol-A and thus can have high heat resistance. Polycarbonate resins also can have flexibility and rigidity due to a carbonyl group of a carbonate group having high rotating mobility.
In addition, a polycarbonate resin is an amorphous polymer and thus can have excellent transparency characteristics. Further, a polycarbonate resin can have excellent impact resistance and compatibility with other resins and the like. Polycarbonate resins, however, can also have poor fluidity and thus may also be alloyed with various resins to improve workability and post processability.
Among the alloys, a polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS) alloy can have excellent durability, formability, heat resistance, impact resistance, and the like and is applied to various fields such as electricity/electronics, automobiles, architecture, miscellaneous real life materials, and the like.
However, the PC/ABS alloy can lack resistance to chemicals used in cosmetics and air fresheners used inside a vehicle and thus may be damaged when used as an auto interior material.
A polyester resin can have excellent mechanical characteristics, electric characteristics, chemical resistance, and the like and particularly, a fast crystallization rate and thus excellent molding workability. Polyester resins, however, can have a low glass transition temperature and thus low heat resistance and also, low impact resistance at room temperature and a low temperature.
One attempt to improve chemical resistance of polycarbonate resins includes increasing the molecular weight of the polycarbonate resin. This can, however, deteriorate formability and thus limit the size of parts made using the same.
In addition, there have been efforts to use a polyester/polycarbonate (polyester/PC) alloy in which the polyester resin has a fast crystallization rate. As an amount of the polyester resin is increased, however, heat resistance is deteriorated, and a deviation in terms of appearance and mechanical properties may occur due to phase instability between the polyester and the polycarbonate.
Accordingly, there is a need for a thermoplastic resin composition having excellent chemical resistance, impact resistance, heat resistance, and formability compared with a conventional PC/ABS alloy and polyester/PC alloy.